KVM: selftests: fix supported_flags for riscv

commit 849c181 ("KVM: selftests: fix supported_flags for aarch64")
fixed the set-memory-region test for aarch64 by declaring the read-only
flag is supported. riscv also supports the read-only flag. Fix it too.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240403123300.63923-2-ajones@ventanamicro.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: Andrew Jones

tools/testing/selftests/kvm/set_memory_region_test.c

@@ -333,7 +333,7 @@ static void test_invalid_memory_region_flags(void)
 	struct kvm_vm *vm;
 	int r, i;
 
-#if defined __aarch64__ || defined __x86_64__
+#if defined __aarch64__ || defined __riscv || defined __x86_64__
 	supported_flags |= KVM_MEM_READONLY;
 #endif